I have 2 HDDs in my PC. Ubuntu is turning off the secondary HDD very quickly after about 15 minutes, which is short for me. I need to control this time. How can I do it?

I tried GNOME power management but did not find it useful.


13 Answers 13


Have a look at hdparm.

From the manual (man hdparm on the command line):

-S     Put the drive into idle (low-power) mode,  and  also  set  the  standby  (spindown)
       timeout  for  the  drive.  This timeout value is used by the drive to determine how
       long to wait (with no disk activity) before turning off the spindle motor  to  save
       power.   Under  such  circumstances,  the  drive  may take as long as 30 seconds to
       respond to a subsequent disk access, though most  drives  are  much  quicker.   The
       encoding  of  the  timeout  value  is  somewhat  peculiar.   A  value of zero means
       "timeouts are disabled": the device will  not  automatically  enter  standby  mode.
       Values  from  1  to  240  specify  multiples of 5 seconds, yielding timeouts from 5
       seconds to 20 minutes.  Values from 241 to 251 specify from 1 to  11  units  of  30
       minutes,  yielding timeouts from 30 minutes to 5.5 hours.  A value of 252 signifies
       a timeout of 21 minutes. A value  of  253  sets  a  vendor-defined  timeout  period
       between  8  and  12 hours, and the value 254 is reserved.  255 is interpreted as 21
       minutes plus 15 seconds.  Note that some  older  drives  may  have  very  different
       interpretations of these values.


sudo hdparm -I /dev/sdb | grep level

will show the current spindown value, for example:

Advanced power management level: 254

From the manual, 254 is reserved, so I expect it to be Ubuntu's default (can anyone confirm/expand on this please?).


  • sudo hdparm -S 25 /dev/sdb = spindown after 25*5 seconds.

  • sudo hdparm -S 245 /dev/sdb = spindown after (245-240)*30 minutes.

  • 6
    Regarding lzap's answer you seem to grep for APM (-B parm) but talk about -S the spindown. Do you also know something about APM?
    – turbo
    Mar 13, 2012 at 18:09
  • 5
    The current -B setting is shown as indicated above. How can I see the current -S setting?
    – SabreWolfy
    Jun 22, 2012 at 22:57
  • 12
    sudo hdparm -y /dev/sdb kills the beast immediately
    – siamii
    Mar 3, 2013 at 23:20
  • 1
    @SabreWolfy I've asked that as a separate question: How can I find out the current drive spin-down time?
    – ændrük
    Apr 13, 2013 at 4:12
  • 1
    When I use "-S" to set a spindown time, it tells me it's going to step standby to the time I specify, but when I immediately read it back with "-I" it tells me the level is 254.
    – Michael
    Aug 28, 2018 at 4:46

Disk Utility -> select HDD drive -> click on the "More actions..." icon on the top right corner -> Drive settings...

Mine is looks like this: screenshot

  • 11
    Easiest by far, thanks! (BTW the package you need to install if you don't have this is gnome-disk-utility. Feb 10, 2014 at 21:14
  • 2
    Why most of tips involve error prone file editing or console operations, while user friendly tools like this already exits!
    – WooYek
    Jul 8, 2017 at 13:37
  • 1
    @WooYek It's nice to have more options, for those who don't want to have to install gnome, for instance.
    – Michael
    Aug 28, 2018 at 0:02
  • 2
    @wooyek this is how Linux works though. The UI doesn’t do anything other than what people offered as a solution. This isn’t a forum that states to support non technical users first. It’s a forum that finds concise answers to problems. hdparm is the core Tool to achieve this. It’s like complaining that someone explains to you what algebra to use to solve a mathematical problem you have and someone else says „just use a calculator“. May 27, 2020 at 8:24
  • 2
    @WooYek The simple fact of the matter is that on Linux we have many choices of desktop environment available, so trying to hand-hold someone through a GUI solution can often be much more hassle than just telling them how to edit the exact same config file that the GUI tools modify, because some people use KDE, others use Gnome, still others use some other random desktop environment that came with their distro. Sure, this answer was simple (for a Gnome user) but would very likely totally fail for someone on another desktop.
    – Spam Hater
    Oct 11, 2020 at 18:33

If you're interested on do the hdparm's setting persistent between reboots, instead of adding it to the crontab, you can use the /etc/hdparm.conf. I have the following, note the use of capital S, not lowercase:

command_line {
    hdparm -S 25 /dev/disk/by-uuid/f6c52265-d89f-43a4-b03b-302c3dadb215 

Add that line replacing the UUID by yours, or also you may specify the device using /dev/sdX format. You can find out your disk's UUID with the command sudo blkid.

  • 4
    Is it correct to use command_line nowadays? I have different examples in my /etc/hdparm?
    – Dims
    Oct 22, 2014 at 7:19
  • 3
    Ondra Žižka's answer seems to be more up to date.
    – Raphael
    Apr 28, 2018 at 17:28
  1. Find your disk's UUID.

    sudo lsblk --output NAME,FSTYPE,LABEL,UUID,MODE
  2. Edit /etc/hdparm.conf

    sudo -H gedit /etc/hdparm.conf  # Be careful from now on
  3. Look for spindown-time or your disk settings section.

    /dev/disk/by-label/4TB {
        spindown_time = 1200
  4. I prefer to refer to the disk by UUID which remains the same across different installations (unless you change it in the HW itself).

    /dev/disk/by-uuid/91e32677-0656-45b8-bcf5-14acce39d9c2 {
        spindown_time = 1200
  5. If the init script causes boot problems, you can pass nohdparm on the kernel command line, and the script will not be run.

  • What are the units for that parameter?
    – detly
    Aug 6, 2016 at 8:55
  • IIRC, it's seconds. Or maybe this is the parameter which had wild rules like "if it's under 10, then its tens of seconds, if under 100, then it's minutes", and such. I'd need to find. Aug 9, 2016 at 13:01
  • 2
    It's not units, check this: wiki.archlinux.org/index.php/Hdparm Aug 9, 2016 at 13:07
  • Cheers, for some reason I couldn't find it in man hdparm.conf.
    – detly
    Aug 9, 2016 at 13:09
  • man hdparm.conf indirectly reads that the value is passed to -S hence for values < 255 should be compatible with rule in the top answer. Any further information is welcomed.
    – dma_k
    Jan 18, 2018 at 17:23

After spending hours and hours I discovered that my WDC drive do not support hdparm -S command, no matter idle3 attribute value (google: idle3ctl). And that is common problem with WD drives. But I'm pleased to announce that hd-idle (http://hd-idle.sourceforge.net/) works flawlessly. If installed from dpkg-builded package (see Installation notes), it creates daemon on both ubuntu and debian (config is in /etc/default/hd-idle). Works well after resuming from hibernation as well.

mc default # ps aux | grep hd-idle | grep -v grep | cut -c 66- ; for f in [a-d] ; do hdparm -C /dev/sd$f | grep -v "^$" ; done
/usr/sbin/hd-idle -i 1800 -a sdc -i 600 -a sdd -i 60 -l /var/log/hd-idle.log
 drive state is:  active/idle
 drive state is:  standby
 drive state is:  standby
 drive state is:  standby


I discovered that the spindown behavior of Samsung HD204UI depends on the APM level (hdparm -B). If the APM level is 127, the spindown timeout is 10 s. If the APM level is 150, the spindown timeout is defined by the -S option.


I add something like:

@reboot sudo hdparm -S244 /dev/disk/by-uuid/71492809-e463-41fa-99e2-c09e9ca90c8e  > /dev/null 2> /dev/null

to root's crontab. Using uuid is better I think because sda/sdb etc. seems to change with every reboot


In Ubuntu 14.04

Disks > highlight drive > click the gear in the upper right hand corner > Drive Settings > now you have Standby, APM, AAM and Write Cache settings in an easy to use GUI!

  • How do you make this work? I have set this, and after reboot if i go back in it has remembered that the drive should power down, but it never does. hdparm -C always shows it is active and only running hdparm -S xxx from the commandline makes it work.
    – dan carter
    Jul 20, 2014 at 11:10
  • 1
    Where do you find "Disks"?
    – nealmcb
    Jan 14, 2015 at 1:14

An important note: unlike the main answer, it seems that

sudo hdparm -I /dev/sdb | grep level 
# Advanced power management level: 254

does not show the current spindown value (that we can set with hdparm -S, as desired by OP), but rather displays the value set with hdparm -M:

hdparm -M 128   # Set acoustic management to 'quiet'
hdparm -M 254   # Set acoustic management to 'fast'

I had no luck with hdparm on an external HDD mounted in a USB enclosure, which I use to serve media with minidlna.

I came across an idea from here: https://serverfault.com/questions/562738/keeping-usb-backup-drive-from-sleeping-while-mounted

Best results come from using the disk's uuid, which you can find with:

sudo blkid

The following method does require root access, but so does hdparm. This uses crontab to read a random block from the drive every 5 minutes and ignores all messages. To make sure you have the right UUID, test it on the command line like this (make sure you use your desired UUID, not this one):

sudo dd if=/dev/disk/by-uuid/f01df4b5-6865-476a-8d3b-597cbd886d41 of=/dev/null count=1 skip=$RANDOM

You should see output like this:

1+0 records in
1+0 records out
512 bytes copied, 0.000738308 s, 693 kB/s`

To suppress this message, which could end up getting written somewhere, potentially the / filesystem (which is on an SSD in my case), below is what I'm using in the root crontab. You get there with

sudo crontab -e

Then, under the comments:

*/5 * * * * bash -c 'dd if=/dev/disk/by-uuid/f01df4b5-6865-476a-8d3b-597cbd886d41 of=/dev/null count=1 skip=$RANDOM' >/dev/null 2>&1

Hope this helps someone else with similar issues. Unfortunately, this still gets written to the syslog, but there are potentially ways to suppress that; see this ServerFault post.

[edit] 2017-01-07 09:02:

I was able to suppress these messages by editing /etc/rsyslog.d/50-default.conf to change this line:

*.*;auth,authpriv.none -/var/log/syslog

to this:

*.*;cron,auth,authpriv.none -/var/log/syslog

Unfortunately, this suppresses all cron messages; I could not get cron to redirect logging off the root filesystem (which is on an aging SSD in my case, so I want to limit writes), but as this is just a home server, I am probably not missing out on much. Would definitely not recommend this strategy for a production machine.


on ubuntu 18.04 to 20.04, you can change drive setting standby timeout at:
search Disks in the launcher > select your disk > click on ⋮ at menu bar next to minimize the window button > Drive Settings > use slider to set timeout

Screenshot on ubuntu 20.04


On Debian, with WD drives, I find that setting any level with hdparm -S results in the drive returning a level 254 on subsequent hdparm -I. So I'm really not sure if they're spinning down or not. I think they are still spinning down.

These drives are on a server array, and I really don't want them to ever spin down. In the past I've kludged this by setting a cron job to update a file every few minutes.


I have discovered that

sudo hdparam -S 0 /dev/sda1

on my disk gives this output:

setting standby to 0 (off)

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